1. Field of the Invention
The present invention relates to thin film forming apparatus for and thin film forming method of forming a thin film pattern or a plurality of thin films on a surface of any of a variety of substrates such as a semiconductor wafer, a glass substrate for a liquid-crystal-display-panel, a glass substrate for a plasma-display-panel, a photo mask substrate, a print-circuit board and the like.
2. Description of Related Art
A damascene method is known as an example of the method of forming a metallic wiring such as a copper wiring or the like on a surface of a semiconductor wafer (hereinafter simply referred to as wafer). FIGS. 11A to 11D show a wiring forming process according to the damascene method.
Formed on the wafer 1 is an insulating film 2, on which there are pattern-formed resists 3 having openings 3a corresponding to a metallic wiring pattern to be formed (FIG. 11A). With the use of the resists 3 as masks, etching is conducted, thus forming, in the insulating film 2, openings or recess portions 2a corresponding to the wiring pattern to be formed (FIG. 11B).
Then, a wiring metallic film 4 is formed all over the surface of the wafer 1 in such thickness that the openings or recess portions 2a are entirely buried (FIG. 11C). Then, according to a CMP (chemical mechanical polishing) method, the metallic film 4 is ground or polished until the surface of the insulating film 2 is exposed. This forms metallic wiring patterns 4W embedded in the openings or recess portions 2a in the insulating film 2 as shown in FIG. 11D.
However, the wiring forming process above-mentioned requires not only patterning with photolithography applied to the insulating film 2 on the wafer 1, but also grinding or polishing the entire surface of the wiring metallic film 4 according to the CMP method. This makes the process complicated, disadvantageously increasing the wiring pattern forming cost.
On the other hand, a transfer method is known as an example of the method of forming an interlayer insulating film on the surface of a semiconductor wafer. According to this transfer method, another sheet different from the semiconductor wafer is coated at its surface with an interlayer insulating film material, thus forming a coated film. This sheet having the coated film formed thereon and the semiconductor wafer are laminated on each other. Then, only the sheet is separated from the semiconductor wafer, thus transferring the coated film from the sheet to the semiconductor wafer.
The use of the thin film forming method according to this transfer method, can eliminate the problem of voids encountered with forming of an SOG (Spin On Glass) layer with the use of a spin-coater. Further, a flat interlayer insulating film can be formed without a flattening processing such as a CMP method or the like.
In a recent semiconductor integrated circuit having a complicated arrangement, however, a number of thin films are formed on the surface of the substrate as typically seen in the case where multi-layer wirings are formed on a semiconductor substrate. In such a case, when there is used the prior art above-mentioned in which only one-type thin film is transferred, at one time, from the sheet to the semiconductor wafer, it is required to execute the transferring processing many times. This complicates the production process, thus disadvantageously increasing the semiconductor production cost.